The development of wireless communication and data transmission structures allows two stations to transmit two or more separate streams or sections of data with a single transmission unit. In some applications, the two separate streams or sections may be considered as two separate “services,” such as voice communication, a section of video stream, a section of data file, text, or e-mail, or a section of an audio stream, etc. A transmission unit that is self-contained or consecutive in time may be considered as a protocol data unit, a unit that may be defined or governed by transmission protocols. In other words, various wireless communication mechanisms may allow one station to transmit or communicate two or more service data units (SDUs) within a single protocol data unit (PDU).
In an exemplary wireless communication system, a mobile station may multiplex multiple service data units (SDUs) into a protocol data unit (PDU) before transmitting the PDU. To facilitate de-multiplexing of the PDU at a receiving station, each of the SDUs in the PDU may include a length indicator for indicating the length of the corresponding SDU. The SDU length indicators usually have a predetermined, fixed length that does not vary from one to another. The design offers a length of the indicator that is large enough to support the longest SDU of all of the transmissions. Although easy to implement, the length indicators occupy spaces that may be otherwise available for transmissions of data content and may require certain signaling overhead.
Using an example for illustration, the length of an i-th length indicator may be expressed as:Ii=M, for i=1 to n, n being a natural number,                wherein Ii is the length of the i-th indicator in a PDU having a number of “n” SDUs, and “M” is a predetermined, fix length, which can be represented in the number of bits.        
As an alternative technique, the length indicators may have their lengths dependent on the size of a PDU. Accordingly, the length of an j-th length indicator may be:Ij=┌log2B┐, for j=1 to n, n being a natural number,                wherein Ij is the length of the j-th indicator in a PDU having a number of “n” SDUs, and “B” is the size of the PDU in bits.        
Certain conventional designs may require signaling overhead due to the transmission space or resource needed for some indicators, such as the indicators for the SDUs illustrated here or other indicators. It may be desirable to have alternative designs that may be suitable for some applications or may overcome or be configured to overcome one or more disadvantages associated with some conventional designs.